Bolster-spring.



E. J. HARVEY.

BOLSTER SPRING. APPLICATION FILED JUNE-I13, 1 914.

Patented Feb. 1, 1916.

HE COLUMBIA PLA ccmAPl-l c0 SH NnTo D c EDWARD JrHAR1VEY, OF RACINE,WISCONSIN.

BOLSTER-SPRING.

SpecificationbfiLetters Patent. Patented Feb. 1, 1916.

Application filed. June 13, 1914. Serial No. 844,857.

To all whom it may concern:

Be it known that I, EDWARD J. HARVEY, a citizen of the United States,residing at the city of Racine, county of Racine, and State ofVisconsin, have invented new and useful Improvements in Bolster-Springs,of which the following is a specification.

My invention relates to improvements in bolster springs for wagons.

The object of my invention, is among other things, to porting bars, withwhich the springs are connected, that the point of contact of thesprings with such bars will be increased as the weight of the loadincreases, whereby the strain will be extended from the center towardthe respective ends of said bars, as the latter are depressed by theload, and whereby the resistance of the spring to the load will beincreased as the point of contact of the spring with the bars isincreased, and also whereby I am enabled in some cases to use a singleplate only in the construction of the respective spring, and whereby aless number of plates are necessary than would otherwise be required forsupporting a given load. It is a well known fact, that springs asordinarily constructed to support a heavy load, would be too rigid touse with comfort with a light load. In other words, heavy springs aretoo rigid to use with comfort when subjected to a light load, while bymy improvements a light spring which may be used with comfort with alight load becomes more rigid in proportion to the weight upon it, andconsequently a given bolster spring thus made is adapted to be used withboth-light and heavy loads.

My invention is further explained by reference to the accompanyingdrawings, in which- Figure 1 represents a side view showing the springas it appears before it is subjected to the weight of a load. Fig. 2represents the same device showing the spring as it appears underpressure of a load. Fig. 3 is a vertical section drawn on line 00, w ofFig. 1, and Fig. 4 is a vertical section drawn on line y, y of Fig. 1.

so construct the box sup- Like parts are identified by the samereferencenumerals throughout the several views. I a

1 is a wagon bolster of ordinary construction.

2 represents the bolster spring, the respective ends of which arepivotally connected with the bolster 1 through the U-shaped stirrups 3.The respective ends of the springs are provided with circular bends 4,which inclose the ends of the stirrups 8, while the center portion ofthe stirrups rests upon the bolster 1 and are retained in place by theplates 5 and circular brackets 6. To the center of each spring isrigidly secured a bar 7, by the U-shaped keepers 8 and nuts 9, whichnuts have threaded bearings on the respective ends of the keepers 8. Thelower side of the bars 7 are straight and are adapted asthe springs arecompressed, from the position shown in Fig. 1 to that shown in Fig.2, tobe brought in direct contact with the upper side of the springs, asshown in said Fig. 2, whereby the area of the point of contact uponwhich the load rests is increased in proportion to such load and wherebythe rigidity of the spring is also increased in proportion to its load.The respective ends of the bars 7 are preferably connected together bymetal plates 10 and bolts 11.. 1

It will be understood that the ordinary wagon box, not shown, is adaptedto rest at its respective ends upon the bars 7, and that such box isfree to move upward and downward with the load between the stakes 12, 12as the springs are compressed and expanded by the jarring movement ofthe vehicle with which they are connected.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent, is-

The combination with a bar having a flat surface, of a leaf springsecured to said flat surface of the bar, said spring projectingoutwardly from the point of connection longitudinally of the bar anddiverging therefrom in a continuous curve from the portion in contactwith the bar substantially to the outer end of the spring, the

form and resilience of said spring being load to be carried,substantially as rle- 10 such that the area of continuous contactscribed.

with the bar Will progressively increase in In testimony whereof I affiXmy signature direct proportion to thefload aihd tllIOLghin the presenceof tWo Witnesses.

out the entire length 0 said at sur ace 7' opposed to the spring,whereby the spring EDWARD HARVEX' may be progressively reinforced by thebar Vvitnesses:

from the point of connection to theend of H. N. BAooN,

the area of contact in accordance with the THos. ALLEN.

Copies of this patent may be obtained for five centsteach, by addressingthe Commissioner of Patents. Washington, I). G.

